We reanalyze the conditions under which we have a primordial thermal population of axions. We extend a previous study and take into account processes involving gluons and quarks. We conclude that if the Peccei Quinn scale satisfies Fa,1.231012 GeV there is thermal axion production. In this case, a period in the early universe exists where axions would interact with the QCD plasma and we point out that nonthermal axions
produced before the end of this period would thermalize.